As we come on the air an incredible drama is still unfolding at a shopping mall taken over by terrorists in kenya. It happened in the city of nairobi, the kind of mall familiar to all of us. Filled with stores and restaurants. Dozens of people have been killed. 1,000 were rescued. Many of them children at the mall for a special event. And tonight we'll try to answer some big questions. Who are these terrorists and could they target the united states? And where did all those people hide before they escaped? We have team coverage of the mall massacre and we'll begin with abc's linsey davis right there on the scene tonight. Linsey. Reporter: A moment of terror. Parents clutched their children running as fast as they could. Those small scared face, those frantic hug, a saturday shattered by the calculated attack. Explosions rang out and today, more than 48 hours into the siege, black smoke billowed. I am crouched ducking for cover. I'm not sure if you can hear but we're hearing some heavy gunfire. Some screams just now just if you look over this building right here in the direction of the mall, you can see the dark billowing smoke in the midst of this. The mall is a 300,000-square-foot upscale family oasis as big as many american malls with 80 stores, a movie theater, supermarket and food court. Authorities now say as many as 15 members of al shabab, the al qaeda affiliated somali terrorist organization stormed the building saturday afternoon armed with guns and grenades some dressed as women. Near the entrance arnold was working near a burger bar when it began. I thought we were going to die. I covered and covered my face so when they come there they see like I'm dead. Reporter: American nick handler was separated from his pregnant wife when the shooting began and rushed to find an exit carrying his daughter julia in had is arms. Felt a loud explosion followed by gunshots and immediately grabbed her and luckily was right by the door so I could sprint out. Reporter: A few doors down, shoppers in the supermarket took cover among the shelves of food. Searching desperately for loved ones. They are shooting. It was pop, pop, pop, pop. And the families and people are not waking up. Reporter: While some militants hunkered down inside the supermarket, others made their way to upper floors. All the way to the roof where children's cooking contest was under way trampolines were set up outside. Special forces descended on the mall making their way to upper floors engaging in gunfire with the terrorists, evacuating pan ined shoppers down escalators with their hands in the air. Rescuing people in hiding like this woman in an upstairs restaurant who took cover inside an air vent. American elaine dang was rushed to a local hospital. I just got out of surgery. I'm okay. I'm very grateful to be alive. Reporter: You can still smell the smoke in the air but kenyan officials say the fire has been contained. They have spent a large part of the day clearing the mall, going through every square foot searching for additional hostages, terrorists and bodies,

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